FIG. 1 is a perspective view of a conventional commercial-grade prior-art cylindrical lockset 4, having internal rose cages 5 that house lever return springs. FIG. 2 is a perspective view of the lockset 4 of FIG. 1 with trim removed, revealing a single compartment lock body 6 that contains only the retractor but not the return springs. Lockset 4 is bulky, and its trim (because it houses internal rose cages 5) is very large and prominent.
FIG. 3 is a perspective view of another conventional commercial-grade prior-art cylindrical lockset 7, in which large cast spindle bearings 8 are provided to house the lever return springs. FIG. 4 is a perspective view of the lockset 7 of FIG. 3 with trim removed, revealing a lock cage and cover 9 that contains only the refractor and large cast spindle bearings 8 housing the lever return springs. Lockset 7 is relatively expensive to fabricate, due to the process of casting the spindle bearings 8. Trim for lockset 4 is also relatively large and prominent.
There is a need for a more innovative cylindrical lockset that is cost-effective and yet provides desired strength, durability, versatility, and functionality characteristics.
FIG. 5 illustrates a conventional cantilever-type knob catch assembly housed in a spindle 69, the knob catch assembly including an elongated cantilevered spring 98 held within an elongated axial slot 68 of the spindle 69. Typically, either the cantilevered spring design yields a handle-retaining force that is weaker than desired, or the spring is so stiff that it too easily and quickly overstressed. Accordingly, there is a need for an improved knob catch assembly for a tubular spindle that provides desired strength and durability characteristics.
The present invention described below, however, can be characterized in many different ways, not all of which are limited by the above-mentioned needs or design constraints.